Olympus OM-1/2/3/4
The Olympus OM system was released by Olympus in 1972. The Olympus OM bodies were divided in a high range and a middle range. The one digit models were the high range. The middle range were the two digit models OM-10/20/30/40. The OM-1 and OM-2 http://static.flickr.com/26/45323314_727f87d37b_m.jpg The very first model was presented at the Photokina of Köln in 1972 and was called the Olympus M-1. Very soon a complaint from Leica forced Olympus to rename the M-1 to OM-1, and apart from the name the two models are identical. However bodies and lenses with the M name are very rare and sought after by collectors. The OM-1 is an all mechanical single lens reflex. It has a very large viewfinder with interchangeable screens but a fixed prism. It also has a through the lens exposure meter commanding a needle visible in the viewfinder. It has a very compact body, which will be essentially retained on later models. Originally, you had to modify the bottom plate to mount a motor winder on the OM-1. In 1974 was launched the OM-1MD, MD for Motor Drive, on which a motor drive can be attached with no modification. This new version wears a small plate marked MD on the front. In 1975 in a salon in Paris was presented the OM-2, which is the automatic version of the OM-1. The body is externally the same, but the shutter is an electronic one and the exposition is automatic with aperture priority, or manual. The exposure meter is able to measure the quantity of light reflected by the film and compensate any variation of light during the exposure. It was the first time this feature was introduced. The OM-2 introduced for the first time the automation of the flash with a through the lens measure. This feature simplifies greatly the flash exposure, and is today used in all the cameras. The dedicated flash is the Olympus Quick Auto 310, and the system is unfortunately not compatible with the later T series flash units introduced with the OM-1n and OM-2n. In 1979 were introduced the OM-1n and OM-2n. The OM-1n is the same as the OM-1 with the following modifications: * a redesigned film advance lever * a flash ready/sufficient flash LED in the viewfinder, as well as automatic X-sync regardless of the position of the speed ring and the FP/X switch, when it is used with a T-series flash unit mounted on Flash Shoe 4. The OM-2n, based on the OM-2, has the same modifications plus: * a direct contact inside for Recordata Backs * an exposure compensation warning flag * full-frame averaging at all shutter speeds * 120 second exposure limit on auto (OM-2 limit was 60 seconds). All these models existed in chrome or black, except the M-1 for which it seems no black body is known. The OM-2SP / OM-2S http://static.flickr.com/24/44931866_d7b07432e2_m.jpg The OM-2SP was introduced in 1986, after the OM-3 and OM-4. On some markets, it was called OM-2S. Although its name suggests it is a continuation of the OM-2, it has more in common with the OM-4. Compared to the OM-2n, the OM-2SP adds: * programmed exposure automation (camera chooses both aperture and shutter speed), added to the aperture priority and manual modes * a spot meter for use in manual mode * a slightly modified body, with the hot shoe not removeable * the ISO range is extended from 1600 to 3200 * the viewfinder indicators are LCDs * the self timer has mirror prefire. On some markets, the OM-2SP was called OM-2S. The OM-2SP / OM-2S only existed in black. The OM-3 and OM-4 The OM-4 is a higher end body, released in 1983. It introduced a new light metering system in a body slightly modified from the OM-2. The exposure meter gives the choice between average and spot metering, and can remember up to eight spot measures, calculating the mean between all of them. This system is called multi-spot. It also incorporates an exposure corrector, and the highest speed is now 1/2000. The OM-4 was released about the same time as the Nikon FA, which introduced the matricial metering. The two systems were innovative but quite different, with the OM-4 the photographer is assisted but has to think more, with the FA the camera begins to think for him. Of course today everyone has taken the path shown by the FA. The OM-3 is a mechanical body with the same metering system as the OM-4, it is basically the same camera with no automation and with a mechanical shutter, but retaining the multi-spot system. It has no TTL flash automation. It is a niche camera, released in 1984, and which did not sell in great quantities. People who wanted a mechanical body went on buying the OM-1n, which was sold at least until 1987, and those who were attracted by the multi-spot system would buy an OM-4. Both the OM-3 and the OM-4 only existed in black. The OM-3Ti and OM-4Ti / OM-4T The OM-4Ti was released in 1987 and replaced the OM-4. It was called OM-4T on some markets. It is the same body as the OM-4 except it is made in titanium, and it introduces a new flash system, with a stroboscopic flash unit called the F-280, allowing to take flash pictures with any speed until the maximum 1/2000. This system was called Super FP sync. It was an answer to one of the OM's weaknesses: the X sync speed is low at 1/60. The OM-4Ti was released first with a champagne finish, then later in a black finish. The OM-3Ti is a limited release in 1995 of a mechanical body, basically the same as the OM-4Ti with a mechanical shutter. It has the multi-spot metering, the Super FP sync, and the TTL flash automation, a rare feature on a mechanical body. At the same time was released a 35-80/2.8 zoom in OM mount. Links * OM SLR FAQ * OM-1(n), OM-2(n) and OM-2SP at Modern Classics Reviews and Opinions * Manual Camera User's Opinion: ** on M-1 ** on OM-1 ** on OM-3 ** on OM-3Ti ** on OM-4Ti Repairs * Olympus hardware resource page - online repair manuals * OM-1 Repair - Basic shutter job * Top Cover removal * Prism Foam replacement